Data receivers typically down-convert signals from a high frequency RF to a lower intermediate frequency IF. This is done to reduce the number of complex and power hungry RF circuits. This down-conversion is done using a mixer. Mixers may either be passive or active. Passive mixers are beneficial because they consume little or no power. However, they exhibit poor conversion gain, especially at small signal levels. Active mixers can achieve higher conversion gain, but use large amounts of power. For systems requiring very long battery life, the power consumption of an active mixer may be too high. For these applications, typically a passive diode mixer is used. Receivers using passive diode mixers typically have poor sensitivity to low conversion gain of the diode. Thus, the transmitted signal must have large power. This places restraints on the transmitter and message transmission distance.